ICU-acquired weakness represents a common and often devastating disease process which affects greater than 50% of critically ill patients. This pathogenesis of this acquired disease is multifactorial and results in variable severity, ranging from mild, transient to severe, permanent dysfunction of peripheral nerves in additional to muscle. In affected patients, weakness may persist for months to years after the acute phase of their illness, and has been implicated as a major contributor to decreased functional status and quality of life. Muscle ultrasound has been validated for assessment of muscle size as well as diagnosis of myopathic and neuropathic changes in patients with other known neuromuscular diseases. The use of muscle ultrasound or other imaging modalities for diagnosis or monitoring of ICU-acquired weakness has not been studied, although a single study using muscle ultrasound has shown significant change in muscle size in ICU patients receiving high dose corticosteroids and a prolonged course of paralytic agents. The investigators plan to use multiple modalities to examine skeletal muscle catabolism, function, and structure in patients during critical illness and recovery. The investigators will combine physical exam, hand grip dynamometry, electrophysiologic studies, serum biomarkers, muscle biopsies, and muscle ultrasound to assess a group of critically ill patients during their hospital stay. The investigators will obtain additional data, including neuropsychiatric assessments, severity of illness scores, administration of potentially harmful medications, and pertinent daily laboratory data. This study will last approximately 12 months.

To study the hypothesis that percutaneous muscle biopsy findings consistent with denervation atrophy and myopathic changes will correlate positively with the following assessments of peripheral muscle function. [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:

To study the hypothesis that changes in size and density of pre-selected individual muscles, as assessed by serial bedside ultrasound, will correlate positively with the following assessments of muscle structure and function. [ Time Frame: 12 months ] [ Designated as safety issue: No ]

To study the hypothesis that development of and duration of neurocognitive impairment during critical illness will correlate with changes in muscle size and appearance as measured by serial muscle ultrasound. [ Time Frame: 12 months ] [ Designated as safety issue: No ]

To study the hypothesis that serum and muscle levels of pro-inflammatory cytokines, including IL-1, IL-6, TNF-alpha will correlate with development of ICU-Acquired weakness, as defined by characteristic muscle histopathologic findings or muscle loss. [ Time Frame: 12 month ] [ Designated as safety issue: No ]

Estimated Enrollment:

50

Study Start Date:

November 2008

Estimated Study Completion Date:

December 2016

Primary Completion Date:

January 2010 (Final data collection date for primary outcome measure)

Intervention Details:

Procedure: Biopsy/Ultrasound

obtain muscle biopsies at approximately 14 days of ICU, muscle ultrasound at 3-4 timepoints

Eligibility

Ages Eligible for Study:

18 Years and older (Adult, Senior)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

1. Patients will be included if they are adult, patients in a medical and/or surgical ICU receiving treatment for any of the following:

respiratory failure, or

cardiogenic or septic shock.

Exclusion Criteria:

Cumulative ICU time > 5 days in the past 30 days, not including the current ICU stay, as this might create a state of flux regarding patients' cognitive baseline.

An active substance abuse or psychotic disorder, or a recent (within the past 6 months) serious suicidal gesture necessitating hospitalization. This exclusion will enrich follow-up rates by avoiding patients with whom it is particularly challenging to maintain long-term contact.

Blind, deaf, or unable to speak English, as these conditions would preclude our ability to perform the follow-up evaluation interviews.

Overly moribund and not expected to survive for an additional 24 hours and / or withdrawing life support to focus on comfort measures only.

Prisoners.

Patients who live further than 200 miles from Nashville and who do not regularly visit the Nashville area.

Patients who are homeless and have no secondary contact person available. This exclusion will enrich follow-up rates by avoiding patients with whom it is particularly challenging to maintain long-term contact.

The onset of the current episode of respiratory failure, cardiogenic shock, or septic shock was > 72 hours ago.

Patients who have had cardiac bypass surgery within the past 3 months (including the current hospitalization).

Patients with known Neuromuscular disease prior to admission.

BMI > 40 or patient size that will not make percutaneous muscle biopsy and muscle ultrasound possible.

Patients with a platelet count of less than 30,000.

Contacts and Locations

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To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00937001